Regearing?

[MKETrailblazer]

I most likely do 33s but if something changes go with the 4.56?

[Moots1288]

You can get away with 4.10s and 35's. It would be fine, 4.10s are a perfect median.

[MKETrailblazer]

Alright and do you know where I could get them I've been searching all night but not quite sure where to get them

[Moots1288]

Google? Rock auto? Randys Ring and Pinion?

[MKETrailblazer]

Alright I was just wondering if there was a good company or not

[Moots1288]

Yukon.

[HARDTRAILZ]

4.56 unless buying diffs with 4.10s already in them.

[Moots1288]

4.56 if you're going bigger then 33s

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[Trail X]

That's the big question - what tire OD are you planning on.

Have you looked over this table? http://www.offroadtb.com/articles/tech- ... alculator/

4.10s and 4.56 would both likely be fine with whatever tire you can fit on a TB (probably max is 36" without a SAS or LT conversion). Its really just a matter of the amount of torque you want available on the interstate. If you are in a super flat area, 4.10s are fine. If you have a lot of hills or mountains in your area, I'd go 4.56.

[Shdwdrgn]

Some people might also consider their speedometer adjustment. You can only tune your PCM for 3.42, 3.73, or 4.10 gears, and the tables only allow up to 30.5" tires. Since you are going with larger tires, it may be possible to tune with 3.73 gears, however there have been some weird interactions with the ABS sensors so it's all trial-by-error. If you go with 4.56's I don't think there's any hope of getting your speedo/odometer anywhere close.

I actually got my rear axle and front diff from ebay. Shipping is killer on this stuff though. The crazy thing was they wouldn't deliver the front diff to my house, but they did deliver the pallet with the rear axle right to my driveway.

[Moots1288]

Some people might also consider their speedometer adjustment. You can only tune your PCM for 3.42, 3.73, or 4.10 gears, and the tables only allow up to 30.5" tires. Since you are going with larger tires, it may be possible to tune with 3.73 gears, however there have been some weird interactions with the ABS sensors so it's all trial-by-error. If you go with 4.56's I don't think there's any hope of getting your speedo/odometer anywhere close.

I actually got my rear axle and front diff from ebay. Shipping is killer on this stuff though. The crazy thing was they wouldn't deliver the front diff to my house, but they did deliver the pallet with the rear axle right to my driveway.

That's not true, I have 456 and 33s and an 06 and my pcm corrected my speedo

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[Trail X]

Speedometer calibration is a minor issue. I'd put the ABS working as the higher issue, if only for passing inspections.

Does the 2006+ PCM parameter change also solve the ABS issue?

[Moots1288]

I had no issue with my abs.

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[Shdwdrgn]

That's not true, I have 456 and 33s and an 06 and my pcm corrected my speedo

Yes, that's the difference between 2006+ and earlier models. You CAN make corrections in the PCM. We cannot.

[Moots1288]

That's not true, I have 456 and 33s and an 06 and my pcm corrected my speedo

Yes, that's the difference between 2006+ and earlier models. You CAN make corrections in the PCM. We cannot.

you did not give specific set of years.

[HARDTRAILZ]

Yup. My 2006 was dialed in with a simple retune by PCMofNC

[Shdwdrgn]

No, but MKETrailblazer lists having a 2004.

[HARDTRAILZ]

And he is the only one that will read this thread? Don't we refer me to search and would it not be nice to have all the info included for future reference?

[Shdwdrgn]

Meh... it's a Monday. This whole day has been crap so far.

OK, so for 2002-2005 owners, there may be concerns about the speedo/odometer when regearing and/or changing tire size. There are limited available options for reprogramming the PCM, and some members have had ABS issues after changing gears.

Is that better?

[HARDTRAILZ]